Intake port of lean burn engine and core thereof

Abstract

A linear port and a swirl port constitute an intake port of a lean burn engine by using an integrated core. An injector is placed at a desired location of the linear port and the swirl port, thereby facilitating the manufacture of the cylinder head, reducing manufacturing cost, improving fuel economy of the engine, and reducing toxic exhaust gas.

1. An intake port of a lean burn engine, comprising:
 a connecting part formed at a predetermined location of a linear port and swirl port along a longitudinal direction for providing fuel injected from an injector, wherein said linear port and swirl port are separated from each other except at said connecting part, and wherein said connecting part comprises:
 two cylinders branching from a circle toward said linear port and said swirl port at a constant angle, wherein said cylinders meet at said single circle where said injector is installed; and 
 expanded parts formed around said cylinders, wherein said expanded parts are:
 formed to expand the sectional area of said cylinders at a connection portion with said linear port and swirl port, wherein said cylinders connect with both said linear port and said swirl port; and 
 formed between an acute angle of said cylinder and said linear port and between an acute angle of said cylinder and said swirl port, wherein said expanded parts include surfaces facing each other between said linear port and said swirl port, wherein said surfaces are configured to be widened for more than or equal to about five degrees, respectively from a central surface between said linear port and said swirl port. 
 
 
 
   
   
     2. The intake port as defined in  claim 1 , wherein said linear port and said swirl port are configured to communicate with each other only at an intersecting surface where said two cylinders of said connecting part intersect each other. 
   
   
     3. The intake port as defined in  claim 1 , wherein said connecting part is located not less than about 90 mm and not more than about 120 mm from a valve surface. 
   
   
     4. An intake port core of a lean burn engine, comprising:
 a parting line forming an intake port having a connecting part, said connecting part comprising:
 two cylinders branching from a circle toward a linear port and swirl port at a constant angle; and 
 expanded parts formed around said cylinders, wherein said expanded parts are:
 formed to expand the sectional area of said cylinders at a connection portion with said linear port and swirl port, wherein said cylinders connect with both said linear port and said swirl port; and 
 formed between an acute angle of said cylinder and said linear port and between an acute angle of said cylinder and said swirl port, wherein said expanded parts include surfaces facing each other between said linear port and said swirl port, wherein said surfaces are configured to be widened for more than or equal to about five degrees, respectively from a central surface between said linear port and said swirl port; 
 
 
 wherein said two cylinders meet at said circle where an injector is installed to provide fuel to said linear port and said swirl port, wherein said parting line includes an outer line of an intersecting surface and a lateral ridgeline of two cylinders, and wherein said intersecting surface is formed by an intersection of said two cylinders of said connecting part.